=The Word Vaccine.= Used in connection with the treatment of hay fever, the word _vaccine_ is confusing, for it has been applied to two totally different kinds of medicine, the bacterial vaccines and the pollen extracts. Physicians intending to use _vaccines_ in the treatment of hay fever should make sure which they are using; for the methods and dosage of the one are quite different from those of the other. Sir Almroth Wright, to whom the whole world is indebted for his work in preventive medicine, started the trouble by calling his killed bacteria _vaccines_, having in mind the prevention of bacterial diseases as the familiar vaccine prevented small-pox. Now, _vacca_ is Latin for cow, _vaccinia_ is properly cow-pox and the virus of cow-pox that we use in vaccination against small-pox is properly called _vaccine_. With a paucity of vocabulary unexpected in an Irishman, Wright called his killed bacteria _vaccines_ because he used them to prevent disease, using the word as synonymous with _preventive_. As cow-pox vaccine is the greatest preventive we know, the word _vaccine_ might be justified when applied to the bacterial cultures or to the pollens or to any preventative of disease. But when you leave pure prevention and apply these remedies to the _cure_ of disease, the word _vaccine_ loses even this shadow of justification and the present confusion results. One American house makes a laudable attempt at a more exact terminology by calling the killed cultures of bacteria _bacterins_. Still, the word _vaccine_ for killed bacterial cultures has been advertised so deeply into the medical mind that it is firmly rooted there and not likely to be disturbed by mere considerations of etymology. As for the pollen extracts, they are yet young and impressionable. It would be better to leave off the word _vaccine_ as applied to them and call them what they are, _pollen extracts_. CHAPTER XIII _DIET_ Until recently, diet in hay fever was a matter of avoiding meat and strawberries and the result was usually unsatisfactory. With the conception of hay fever as an anaphylaxis and the recent studies in food anaphylaxis, the subject of diet in hay fever assumes a new and inviting aspect. This new view of diet in hay fever begins with Schloss's masterly study of a case of food anaphylaxis reported in the _American Journal on Diseases of Children_, 1912, No. 6. A good review of the subject with references to the literature will be found in the special Hay Fever and Anaphylaxis number of the _Boston Medical and Surgical Journal_, August 10, 1916, especially the article by Talbot.